Epidemiology, species distribution and outcome of nosocomial Candida spp. bloodstream infection in Shanghai

Candida albicans and Candida glabrata: global priority pathogens

SUMMARYA significant increase in the incidence of Candida-mediated infections has been observed in the last decade, mainly due to rising numbers of susceptible individuals. Recently, the World Health Organization published its first fungal pathogen priority list, with Candida species listed in medium, high, and critical priority categories. This review is a synthesis of information and recent advances in our understanding of two of these species-Candida albicans and Candida glabrata. Of these, C. albicans is the most common cause of candidemia around the world and is categorized as a critical priority pathogen. C. glabrata is considered a high-priority pathogen and has become an increasingly important cause of candidemia in recent years. It is now the second most common causative agent of candidemia in many geographical regions. Despite their differences and phylogenetic divergence, they are successful as pathogens and commensals of humans. Both species can cause a broad variety of infections, ranging from superficial to potentially lethal systemic infections. While they share similarities in certain infection strategies, including tissue adhesion and invasion, they differ significantly in key aspects of their biology, interaction with immune cells, host damage strategies, and metabolic adaptations. Here we provide insights on key aspects of their biology, epidemiology, commensal and pathogenic lifestyles, interactions with the immune system, and antifungal resistance.

Prevalence and Species Distribution of Candida Clinical Isolates in a Tertiary Care Hospital in Ecuador Tested from January 2019 to February 2020

The incidence of candidemia in healthcare centers is associated with high morbidity and mortality. Frequency varies significantly among regions, with some species being more prevalent than others in Latin America. In this study, 191 clinical Candida isolates were collected from a major hospital in Ecuador from January 2019 to February 2020 aiming to assess their prevalence and distribution. After data processing, 168 isolates characterized by the VITEK 2 system were subsequently identified by ITS sequencing. Results showed diverse Candida species distributions, with C. albicans and C. tropicalis being the most prevalent across different clinical sources. In hospitalized individuals, C. tropicalis (38%) and C. albicans (37%) were the most prevalent, followed by, C. parapsilosis (16%), C. glabrata (5%), and other non-Candida albicans (NCA) species (6%). Conversely, C. parapsilosis (48%), C. albicans (20%), and C. glabrata (14%), associated with candidemia, were the most common in blood and CSF. Additionally, uncommon NCA species such as C. haemulonii, C. kefyr, and C. pelliculosa were identified in Ecuador for the first time. Discrepancies in species identification were observed between the VITEK 2 system and ITS sequencing, coinciding at 85%. This highlights the need for ongoing surveillance and identification efforts in Ecuador's clinical and epidemiological settings.

Amphotericin B in the Era of New Antifungals: Where Will It Stand?

Amphotericin B (AmB) has long stood as a cornerstone in the treatment of invasive fungal infections (IFIs), especially among immunocompromised patients. However, the landscape of antifungal therapy is evolving. New antifungal agents, boasting novel mechanisms of action and better safety profiles, are entering the scene, presenting alternatives to AmB's traditional dominance. This shift, prompted by an increase in the incidence of IFIs, the growing demographic of immunocompromised individuals, and changing patterns of fungal resistance, underscores the continuous need for effective treatments. Despite these challenges, AmB's broad efficacy and low resistance rates maintain its essential status in antifungal therapy. Innovations in AmB formulations, such as lipid complexes and liposomal delivery systems, have significantly mitigated its notorious nephrotoxicity and infusion-related reactions, thereby enhancing its clinical utility. Moreover, AmB's efficacy in treating severe and rare fungal infections and its pivotal role as prophylaxis in high-risk settings highlight its value and ongoing relevance. This review examines AmB's standing amidst the ever-changing antifungal landscape, focusing on its enduring significance in current clinical practice and exploring its potential future therapeutic adaptations.

Rising Drug Resistance Among Gram-Negative Pathogens in Bloodstream Infections: A Multicenter Study in Ulanhot, Inner Mongolia (2017-2021)

BACKGROUND Bloodstream infections, which arise when pathogenic microorganisms infiltrate the bloodstream, present a grave health risk. Their potentially lethal nature combined with the ability to severely impair physiological functions underscore the importance of understanding and mitigating such infections. This study aimed to elucidate drug sensitivity profiles and distribution of these pathogens in hospitals in Ulanhot, Inner Mongolia. MATERIAL AND METHODS From 2017 to 2021, we gathered blood culture-positive samples from several hospitals across Ulanhot. Using combined diagnostic techniques, including the instrument method, paper diffusion, and Epsilometer test (E-test), we determined the identity of pathogens and assessed their drug sensitivity. Subsequent data processing with WHONET 5.6 software provided insights into the patterns of microbial distribution and extent of drug resistance. RESULTS Of 2498 pathogenic strains identified, 35.83% were gram-positive, 62.45% were gram-negative, and a smaller fraction of 1.72% were fungi. Escherichia coli and Klebsiella pneumoniae were the primary bacteria, contributing to 35.15% and 15.73% of infections, respectively. Alarmingly, methicillin-resistant strains exhibited pronounced resistance to drugs, notably penicillin G (resistance rates of 80.87% to 100.00%) and erythromycin (resistance rates of 91.16% to 97.28%). Acinetobacter baumannii had a particularly high resistance profile, surpassing Pseudomonas aeruginosa, which exhibited a resistance rate below 30.00%. CONCLUSIONS Ulanhot's primary bloodstream infection agents were gram-negative bacteria, specifically E. coli and K. pneumoniae. The growing drug resistance observed, particularly among strains like A. baumannii, highlights the pressing need for rigorous drug resistance surveillance and the strategic use of antibiotics, ensuring their efficacy is preserved for future medical needs.

Alarming Increase of Azole-Resistant Candida Causing Blood Stream Infections in Oncology Patients in Egypt

Candidemia is a life-threatening invasive fungal infection in immunocompromised patients. The widespread use of azoles and the shift toward non-albicans Candida (NAC) species remarkably increase azole resistance in developing countries. We aimed to study candidemia trends and associated risk factors in oncology patients since they vary geographically, and rapid and appropriate treatment improves outcomes. Vitek 2 was used to identify the Candida species, and the E-test determined their susceptibility to azoles. Candida was the cause of 3.1% (n = 53/1701) of bloodstream infections (BSIs) during a 1-year study. Candida tropicalis was the most predominant species among the 30 candidemia episodes studied (36.7%), followed by C. albicans (33.3%). However, C. krusei, C. guilliermondii, C. pelliculosa, C. parapsilosis, C. famata, and C. inconspicua accounted for 30.0% of the isolates. An increased risk of NAC BSI was significantly associated with chemotherapy and leucopenia (P = 0.036 and 0.016, respectively). However, the multivariable analysis revealed that leucopenia was the only independent risk factor (P = 0.048). Fluconazole and voriconazole resistance were 58.3% and 16.7%, with NAC species showing higher resistance rates than C. albicans. Both fluconazole and voriconazole minimum inhibitory concentration (MIC) median values were higher in NAC than in C. albicans, but only voriconazole was significantly higher (0.220 versus 0.048 μg/ml, P = 0.047). In conclusion, the increased prevalence of NAC BSIs and incredibly high fluconazole resistance rates in cancer patients emphasize the necessity of antifungal stewardship to preserve voriconazole effectiveness, continued surveillance of candidemia, and future studies into azole resistance molecular mechanisms.

Updated estimation of the burden of fungal disease in Vietnam

BACKGROUND

Anecdotally, the burden of fungal diseases in Vietnam is rapidly rising, but there has been no updated estimate on this issue since a previous report in 2015.

OBJECTIVES

In this study, we aimed at estimating the incidence and prevalence of serious fungal infections for the year 2020.

METHODS

We made estimates with a previously described methodology, using reports on the incidence and prevalence of various established risk factors for fungal infections from local, regional or global sources.

RESULTS

We estimated 2,389,661 cases of serious fungal infection occurred in Vietnam in 2020. The most common condition was recurrent vaginal candidiasis (4047/100,000 women annually). Among people living with HIV, we estimated 451 cases of cryptococcal meningitis, 1030 of pneumocystis pneumonia, 166 of histoplasmosis and 1612 of talaromycosis annually. Candidaemia incidence was estimated at 12/100,000 population each year. Owing to its high burden of tuberculosis and respiratory diseases, Vietnam had high rates of severe infections caused by Aspergillus species. Incidence of invasive aspergillosis is 24/100,000 population, allergic bronchopulmonary aspergillosis 78/100,000 and severe asthma with fungal sensitisation 102/100,000. Five-year period prevalence of chronic pulmonary aspergillosis is 120/100,000 population /5-year period. Mucormycosis, fungal keratitis and tinea capitis were estimated at 192, 14,431 and 201 episodes each year, respectively.

CONCLUSIONS

The number of patients with mycoses in Vietnam is likely underestimated due to a lack of local data and limited diagnostic capacity, but at least 2.5% of the population might have some form of serious fungal disease.

Distribution and antifungal susceptibility pattern of Candida species from mainland China: A systematic analysis

Antifungal resistance to Candida pathogens increases morbidity and mortality of immunosuppressive patients, an emerging crisis worldwide. Understanding the Candida prevalence and antifungal susceptibility pattern is necessary to control and treat candidiasis. We aimed to systematically analyse the susceptibility profiles of Candida species published in the last ten years (December 2011 to December 2021) from mainland China. The studies were collected from PubMed, Google Scholar, and Science Direct search engines. Out of 89 included studies, a total of 44,716 Candida isolates were collected, mainly comprising C. albicans (49.36%), C. tropicalis (21.89%), C. parapsilosis (13.92%), and C. glabrata (11.37%). The lowest susceptibility was detected for azole group; fluconazole susceptibilities against C. parapsilosis, C. albicans, C. glabrata, C. tropicalis, C. guilliermondii, C. pelliculosa, and C. auris were 93.25%, 91.6%, 79.4%, 77.95%, 76%, 50%, and 0% respectively. Amphotericin B and anidulafungin were the most susceptible drugs for all Candida species. Resistance to azole was mainly linked with mutations in ERG11, ERG3, ERG4, MRR1-2, MSH-2, and PDR-1 genes. Mutation in FKS-1 and FKS-2 in C. auris and C. glabrata causing resistance to echinocandins was stated in two studies. Gaps in the studies' characteristics were detected, such as 79.77%, 47.19 %, 26.97%, 7.86%, and 4.49% studies did not mention the mortality rates, age, gender, breakpoint reference guidelines, and fungal identification method, respectively. The current study demonstrates the overall antifungal susceptibility pattern of Candida species, gaps in surveillance studies and risk-reduction strategies that could be supportive in candidiasis therapy and for the researchers in their future studies.

Mono-/Bis-Alkenoic Acid Derivatives From an Endophytic Fungus Scopulariopsis candelabrum and Their Antifungal Activity

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.

The proportion, species distribution and dynamic trends of bloodstream infection cases in a tertiary hospital in China, 2010-2019

Background

Recent epidemiological studies on bloodstream infection (BSI) that include the proportion, species distribution and dynamic changes are scarce in China. This study was performed to understand these epidemiological data of BSI over the past 10 years in China.

Methods

Using a prospective nosocomial infection surveillance system, this study was retrospectively performed in one of the largest hospitals in China. The time trend was tested using the Cochran–Armitage trend test in R Programming Language.

Results

From 2010 to 2019, there were totally 9381 episodes of BSI cases out of 1,437,927 adult-hospitalized patients in the hospital, the total proportion of BSI cases was 6.50‰ (6.50 episodes per 1000 adult-hospitalized patients) and the proportion had significantly decreased (8.24–6.07‰, time trend P < 0.001). Among the 9381 episodes of BSI, 93.1% were bacteremia and others were fungemia (6.9%). As the most common species, the composition ratios of coagulase-negative staphylococcus (25.6–32.5%), Escherichia coli (9.8–13.6%) and Klebsiella pneumoniae (5.3–10.4%) had been dynamically increased (all time trends P < 0.05) and the proportion of Pseudomonas aeruginosa had decreased (4.0–2.4%, time trend P = 0.032). However, Staphylococcus aureus (3.3–3.1%) and Acinetobacter baumannii (4.4–4.2%) had not changed significantly (P > 0.05). These common species were consistent with China Antimicrobial Surveillance Network reported in 2018 (2018 CHINET report), but their composition ratios were different. In addition, among bacteremia, the proportion of multidrug-resistant bacteria gradually increased from 52.9 to 68.4% (time trend P < 0.001).

Conclusion

The proportion and species distribution of BSI were dynamically changing along certain trends. These trends deserved more attention from clinicians and researchers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-021-01649-y.

Candida Bloodstream Infections: Changes in Epidemiology and Increase in Drug Resistance

The literature on bloodstream infections (BSIs) have predominantly been biased towards bacteria, given their superior clinical significance in comparison with the other types of microorganisms. Fungal pathogens have epidemiologically received relatively less attention, although they constitute an important proportion of BSI aetiologies. In this review, the authors discuss the clinical relevance of fungal BSIs in the context of Candida species, as well as treatment options for the infections, emphasizing the compelling need to develop newer antifungals and strengthen antimicrobial stewardship programmes in the wake of the rapid spread of antifungal resistance.

Evaluation of the early fluconazole treatment of candidemia protocol with automated short message service alerts: a before-and-after study

BACKGROUND/AIMS

We introduced the Early Fluconazole Treatment in Candidemia (EFTC) protocol in August 2015 to improve the outcomes of patients with candidemia. This study evaluated the effectiveness of the EFTC protocol.

METHODS

We conducted a retrospective before-and-after study among patients in the intensive care units and Hemato-Oncology and General Surgery wards of our hospital between January 2013 and December 2018. The EFTC protocol entailed sending an automatic notification by short message service, feedback to the responsible healthcare worker, and regular standardized education of medical staff. On receiving a notification, physicians prescribed empirical fluconazole immediately. The effectiveness of the EFTC protocol was evaluated by multivariate analysis of risk factors for 30-day mortality.

RESULTS

Of 103 patients with candidemia, 50 were admitted before (pre-EFTC group) and 53 were admitted after (post-EFTC group) the introduction of the EFTC protocol. Patients' mean age ± SD was 67.1 ± 18.6 years, and 55 (53.4%) were male. The mean ± SD time from Candida isolation to antifungal drug administration in the pre-EFTC and post-EFTC groups was 89.1 ± 73.6 and -9.8 ± 63.9 minutes, respectively (p = 0.01). The 30-day mortality in the pre-EFTC and post-EFTC groups was 54.5% (95% confidence interval [CI], 42.3 to 66.7), and 37.6% (95% CI, 26.1 to 49.1), respectively (p = 0.05). In the multivariate analysis, implementation of the EFTC protocol was independently associated with a reduction in 30-day mortality (odds ratio, 0.27; 95% CI, 0.12 to 0.63; p = 0.01).

CONCLUSION

The early f luconazole treatment, monitoring, and education were effective in reducing mortality in patients with candidemia.

CD8+ T cell survival in lethal fungal sepsis was ameliorated by T-cell-specific mTOR deletion

Lethal fungal sepsis causes high morbidity and mortality in intensive care patients. Fungal infections have an immunological basis, and it has been shown in recent studies that decreased CD8⁺ T-cell count in fungal infections is related to prognosis, while the underlying mechanism is still unclear. Here, a lethal fungal sepsis model induced by candidemia was created and we found a decreased CD8⁺ T-cell count and exaggerated apoptosis. Simultaneously, expression of light chain (LC)3B in CD8⁺ T cells increased, along with increased autophagosomes and accumulation of p62 in infected mice. We regulated the activity of the mammalian target of rapamycin (mTOR) pathway using T-cell-specific mTOR/ TSC1 deletion mice. We observed increased number of autophagosomes and expression of LC3B in CD8⁺T cells after T-cell-specific mTOR knockout, while accumulation of p62 was not ameliorated, and there was no increase in the number of autolysosomes. Apoptosis rate and expression of BIM, a pro-apoptotic gene, decreased in CD8⁺ T cells in mTOR-deletion mice but increased in TSC1-deletion mice. Our results showed increased CD8⁺ T-cell death in spleen of lethal fungal sepsis mice, and decreased expression of mTOR ameliorated CD8⁺ T-cell survival. mTOR may be a possible target to reverse CD8⁺ T-cell immune dysfunction in lethal fungal sepsis.

Epidemiology, risk factors, treatment and outcome of Candida bloodstream infections because of Candida albicans and Candida non-albicans in two district general hospitals in the United Kingdom

INTRODUCTION

Bloodstream infections caused by Candida species, known as candidemia are on the rise because of increasing complexity of surgical procedures, patient's underlying co-morbidities and shift in patient's demographics. This study was conducted to evaluate the epidemiology, risk factors, co-morbidities, antifungal treatment and outcomes of candidemia in Candida albicans (C. albicans) and Candida non-albicans (C. non-albicans) in East Sussex Healthcare Trust (ESHT), England.

MATERIAL AND METHODS

This retrospective and prospective study was performed during January 2006 to June 2017.

RESULT

A total of 102 episodes of candidemia on 100 patients (55 males) were identified. C. non-albicans were predominant (55%). All isolates were sensitive to amphotericin B, caspofungin and voriconazole while one C. albicans and five C. non-albicans isolates were resistant to fluconazole. The risk factors in C. albicans and C. non-albicans groups were comparable which included intensive care unit (ICU) stay (15% vs 10%), the presence of intravascular line (35% vs 42%), previous antibiotic exposure (39% vs 49%), surgical intervention (19% vs 19%), mechanical ventilation (5% vs 8%), total parenteral nutrition (30% vs 27%) and urinary catheters (33 vs 38). The comorbidities in both groups (C. albicans and C. non-albicans) were solid organ cancer (15&14), haematology malignancy (1&3), steroid use (14&13), diabetes (9&7) and chemotherapy (2&4). Main sources of candidemia in C. albicans were line (12), respiratory (10) and urinary tracts (6) while line (26) and urinary tract (9) were predominant in C. non-albicans group. Only a small number of patients underwent echocardiography (30%) and ophthalmology reviews (20%). A total of 45 fatal cases were recorded (C. albicans 23). The highest mortality was seen in patients with C. albicans and among them the risk factors were elderly age group > 65 years (17/23), surgical intervention (9/23) and the history of ICU stay (7/23).

CONCLUSION

C. albicans candidemia, >65 years of age and surgical procedure is associated with significant mortality, however, the use of fluconazole has shown the increased survival rate. This study suggests the surveillance of candidemia, and antifungal susceptibility pattern in current practice and the treatment.

Complete Genome Sequence of Candida theae from Hickman Line Infection in an Immunocompromised Child

We present the first whole-genome-sequencing data of a rare fungal species, Candida theae isolated in the context of a Hickman line infection in a patient with juvenile myelomonocytic leukaemia. To our knowledge, this is the first instance of publicly available genomic data for this species. Loci associated with antifungal resistance were referenced against its closely related members of the Candida parapsilosis complex.

Prevalence and Antifungal Susceptibility of Pathogenic Yeasts in China: A 10-Year Retrospective Study in a Teaching Hospital

To determine the dynamic changes of pathogenic yeast prevalence and antifungal susceptibility patterns in tertiary hospitals in China, we analyzed 527 yeast isolates preserved in the Research Center for Medical Mycology at Peking University, Beijing, China, between Jan 2010 and Dec 2019 and correctly identified 19 yeast species by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and ribosomal DNA sequencing. Antifungal susceptibility testing was performed following a Sensititre YeastOne colorimetric microdilution panel with nine clinically available antifungals. The Clinical and Laboratory Standards Institute (CLSI)-approved standard M27-A3 (S4) and newly revised clinical breakpoints or species-specific and method-specific epidemiological cutoff values were used for the interpretation of susceptibility test data. In this study, although Candida albicans was the predominant single species, non-C. albicans species constituted >50% of isolates in 6 out of 10 years, and more rare species were present in the recent 5 years. The non-C. albicans species identified most frequently were Candida parapsilosis sensu stricto, Candida tropicalis, and Candida glabrata. The prevalence of fluconazole and voriconazole resistance in the C. parapsilosis sensu stricto population was <3%, but C. tropicalis exhibited decreased susceptibility to fluconazole (42, 57.5%) and voriconazole (31, 42.5%), and 22 (30.1%) C. tropicalis isolates exhibited wild-type minimum inhibitory concentrations (MICs) to posaconazole. Furthermore, fluconazole and voriconazole cross-resistance prevalence in C. tropicalis was 19 (26.1%). The overall prevalence of fluconazole resistance in the C. glabrata population was 14 (26.9%), and prevalence of isolates exhibiting voriconazole non-wild-type MICs was 33 (63.5%). High-level echinocandin resistance was mainly observed in C. glabrata, and the prevalence rates of isolate resistance to anidulafungin, micafungin, and caspofungin were 5 (9.6%), 5 (9.6%), and 4 (7.7%), respectively. Moreover, one C. glabrata isolate showed multidrug resistant to azoles, echinocandins, and flucytosine. Overall, the 10-year surveillance study showed the increasing prevalence of non-C. albicans species over time; the emergence of azole resistance in C. tropicalis and multidrug resistance in C. glabrata over the years reinforced the need for epidemiological surveillance and monitoring.

Generation and Characterization of Single Chain Variable Fragment against Alpha-Enolase of Candida albicans

Candida albicans (C. albicans) is an opportunistic human pathogen responsible for approximately a half of clinical candidemia. The emerging Candida spp. with resistance to azoles is a major challenge in clinic, suggesting an urgent demand for new drugs and therapeutic strategies. Alpha–enolase (Eno1) is a multifunctional protein and represents an important marker for invasive candidiasis. Thus, C. albicans Eno1 (CaEno1) is believed to be an important target for the development of therapeutic agents and antibody drugs. Recombinant CaEno1 (rCaEno1) was first used to immunize chickens. Subsequently, we used phage display technology to construct two single chain variable fragment (scFv) antibody libraries. A novel biopanning procedure was carried out to screen anti-rCaEno1 scFv antibodies, whose specificities were further characterized. The polyclonal IgY antibodies showed binding to rCaEno1 and native CaEno1. A dominant scFv (CaS1) and its properties were further characterized. CaS1 attenuated the growth of C. albicans and inhibited the binding of CaEno1 to plasminogen. Animal studies showed that CaS1 prolonged the survival rate of mice and zebrafish with candidiasis. The fungal burden in kidney and spleen, as well as level of inflammatory cytokines were significantly reduced in CaS1-treated mice. These results suggest CaS1 has potential of being immunotherapeutic drug against C. albicans infections.

Epidemiology And Antifungal Susceptibility Patterns Of Invasive Fungal Infections From 2012 To 2014 In A Teaching Hospital In Central China

Introduction

As participants of the national China Hospital Invasive Fungal Surveillance Net program, we sought to describe the epidemiology and antifungal susceptibility patterns of yeast isolates obtained from patients with invasive fungal infection at the First Affiliated Hospital of Zhengzhou University, China.

Methods

A total of 434 yeast isolates recovered from blood and other sterile body fluids were identified to species by matrix-assisted laser desorption ionization –time of flight mass spectrometry with or without supplementation by DNA sequencing. Antifungal susceptibilities were determined by Sensititre YeastOne^TM YO10 methodology.

Results

Candida albicans was the most common causative species (33.9% of isolates) but significantly decreased in frequency from 37.2% to 27.7% from 2012 to 2014. C. tropicalis was the next most common pathogen (25.1%), followed by C. parapsilosis complex (17.3%), C. glabrata (9%), and C. pelliculosa (6.7%), with other species comprising 8% of isolates. Caspofungin, micafungin, and anidulafungin exhibited potent in vitro activities against the majority of Candida isolates. Azoles demonstrated in vitro activities against C. albicans with a susceptibility rate of >95% and against C. parapsilosis complex, >95% isolates were susceptible. Among C. tropicalis and C. glabrata isolates, resistance rates to fluconazole and voriconazole were 11.9%, 9.1% and 7.7%, 28.2%, respectively. Of note, C. pelliculosa had a high incidence rate in newborns and high rates of resistance to fluconazole and voriconazole of 55.2% and 41.4%, respectively.

Conclusion

The present study provided valuable local surveillance data on the epidemiology and antifungal susceptibilities of invasive yeast species, which is essential for guiding antifungal treatment protocol development.

Candida blood stream infections observed between 2011 and 2016 in a large Italian University Hospital: A time-based retrospective analysis on epidemiology, biofilm production, antifungal agents consumption and drug-susceptibility

Candida bloodstream infection (BSI) represents a growing infective problem frequently associated to biofilm production due to the utilization of intravascular devices. Candida species distribution (n = 612 strains), their biofilm production and hospital antifungal drug consumption were evaluated in different wards of a tertiary care academic hospital in Italy during the years 2011–2016. In the considered time window, an increasing number of Candida BSI (p = 0.005) and of biofilm producing strains were observed (p<0.0001). Although C. albicans was the species more frequently isolated in BSI with a major biofilm production, an increased involvement of non-albicans species was reported, particularly of C. parapsilosis that displayed a high frequency in catheter infections, and lower biofilm production compared to C. albicans. Although trends of biofilm production were substantially stable in time, a decreasing biofilm production by C. parapsilosis in the Intensive Care Unit (ICU) was observed (p = 0.0041). Principal component analysis displayed a change in antifungal drugs consumption driven by two mutually independent temporal trends, i.e. voriconazole use in the general medicine wards initially, and fluconazole use mainly in the ICU; these factors explain 68.9% and 25.7% of total variance respectively. Moreover, a significant trend (p = 0.003) in fluconazole use during the whole time period considered emerged, particularly in the ICU (p = 0.017), but also in the general medicine wards (p = 0.03). These trends paralleled with significant increase MIC90 of fluconazole (p = 0.05), particularly for C. parapsilosis in the ICU (p = 0.04), with a general and significant decreased trend of the MIC90 values of caspofungin (p = 0.04), and with significant increased MIC50 values for amphotericin B (p = 0.01) over the study period. In conclusion, drug utilization in our hospital turned out to be a putative influencing factor on the ecology of the species, on the increase in time of the biofilm producing strains and on the Candida antifungal susceptibility profile, thus influencing clinical management.

Retrospective Analysis of Microbial Colonization Patterns in Central Venous Catheters, 2013-2017

Objectives

This study was performed to provide epidemiological information on microbial colonization in central venous catheters (CVCs).

Methods

CVCs submitted to Medical Microbiology Laboratory from January 1, 2013, through October 1, 2017, which met our criteria would be included for analysis. Quantitative culture was used for CVCs. The results of culture and related information on CVCs were collected and recorded in detail. The prevalence was calculated, and related factors were analyzed statistically.

Results

A total of 2020 CVCs were submitted for culture and eligible for analysis. Positive microbial culture occurred in 379 catheters with 18.7% (379 of 2020) prevalence of colonization. There were 23 microbial genera and 45 organisms detected. Among the isolated organisms, there were 39 kinds of isolated bacteria and 6 kinds of isolated fungi. Acinetobacter (19.8%) predominated in total isolated microorganisms, followed by Staphylococcus epidermidis (11.3%) and Candida albicans (10.3%). There were no significant differences in isolated organisms and fungal species between different sexes (X² = 2.365, P = 0.50). Conversely, there were significant differences in isolated bacterial and fungal species between different wards and years (X² = 124.046, P = 0.000; X² = 77.064, P = 0.000). A total of 107 (5.3%, 107/2020) CVCs were associated with a diagnosis of central line-associated bloodstream infection (CLABSI). The most common organisms in causing CLABSI were Acinetobacter (23.4%), S. aureus (13.1%), and Candida albicans (12.1%).

Conclusion

The prevalence of microbial colonization in CVCs is still significant and even has gradually changed over time. The study provides a new view of microbial colonization pattern in CVCs and a prevalence of CLABSI, which will facilitate catheter-related infection prevention and control in clinic.

Epidemiology, risk factors and outcomes of Candida albicans vs. non-albicans candidaemia in adult patients in Northeast China

This study aimed to evaluate the clinical characteristics, risk factors and outcomes of adult patients with candidaemia caused by C. albicans vs. non-albicans Candida spp. (NAC). All adult hospitalised cases of candidaemia (2012-2017) at a tertiary hospital in Shenyang were included in the retrospective study, and a total of 180 episodes were analysed. C. parapsilosis was the most frequently isolated species (38.3%), followed by C. albicans (35.6%), C. glabrata (13.9%), C. tropicalis (10%) and others (2.2%). As initial antifungal therapy, 75.0%, 3.9%, 5.6% and 2.2% of patients received fluconazole, caspofungin, micafungin and voriconazole, respectively. Multivariate analyses revealed that total parenteral nutrition was associated with an increased risk of NAC bloodstream infections (BSI) (OR 2.535, 95% CI (1.066-6.026)) vs. C. albicans BSI. Additionally, the presence of a urinary catheter was associated with an increased risk of C. albicans BSI (OR 2.295 (1.129-4.666)) vs. NAC BSI. Moreover, ICU stay (OR 4.013 (1.476-10.906)), renal failure (OR 3.24 (1.084-9.683)), thrombocytopaenia (OR 7.171 (2.152-23.892)) and C. albicans (OR 3.629 (1.352-9.743)) were independent risk factors for candidaemia-related 30-day mortality, while recent cancer surgery was associated with reduced mortality risk (OR 26.479 (2.550-274.918)). All these factors may provide useful information to select initial empirical antifungal agents.

Creation and assessment of a clinical predictive model for candidaemia in patients with candiduria

Candidaemia is the most common clinical presentation of invasive candidiasis and is a major cause of morbidity and mortality. Candiduria is a predictor for candidaemia; however, patient characteristics that are associated with concurrent candidaemia in the setting of candiduria are unclear. Identifying these characteristics could aid in the early detection of systemic disease. We performed a retrospective cohort analysis of hospitalised patients with candiduria at our institution over a 13-year period. Our evaluation of patient characteristics included demographics, comorbidities, medications, procedures, devices, vital signs and laboratory values. We developed a multivariable logistic model to identify factors associated with candidaemia in patients with candiduria. We identified 4240 patients with candiduria, 263 (6.2%) of whom had candidaemia. Predictors for increased risk of candidaemia with candiduria included hospitalisations > 12 days, central venous catheter, parenteral nutrition, haematological and gynaecological malignancy, and receipt of β-lactam/β-lactamase inhibitors. Vital signs and laboratory values associated with candidaemia included elevated heart rate, temperature and creatinine, along with neutropenia and neutrophilia. Factors that demonstrated a decreased risk of candidaemia included diabetes mellitus, gastrostomy and urinary catheter with antibiotic use. The c-statistic was 0.741 (95% CI, 0.710-0.772). We identified a set of clinical characteristics that can predict the presence of candidaemia with candiduria.

Antifungal susceptibility trend and analysis of resistance mechanism for Candida species isolated from bloodstream at a Japanese university hospital

We compared the susceptibility of six commercially available antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin, micafungin, and amphotericin B) against 133 Candida bloodstream isolates between 2008 and 2013 at Aichi Medical University Hospital. C. albicans was the most common isolate, followed by C. parapsilosis, C. glabrata, and C. tropicalis. MIC₉₀s of voriconazole against C. albicans, C. parapsilosis, and C. tropicalis were the lowest and that of micafungin against C. glabrata was the lowest among the agents tested. Of the 133 isolates, two strains were identified as drug-resistant. One was a fluconazole-resistant C. glabrata strain, in which the ATP-binding cassette (ABC) transporter gene expression was upregulated. The other was a micafungin-resistant C. glabrata strain, that had 13 amino acid substitutions in FKS1 and FKS2, including a novel substitution V1342I in FKS1 hotspot 2. We also evaluated the susceptibility of T-2307, a novel class of antifungal agents used in clinical trials, against the fluconazole- and micafungin-resistant C. glabrata strain; the MICs of T-2307 were 0.0039 and 0.0078 μg/mL, respectively. In conclusion, the incidence of bloodstream infection caused by drug-resistant Candida spp. was rare from 2008 to 2013 at our hospital. Of 133 isolates, only two strains of C. glabrata were resistant to azoles or echinocandins, that upregulated the ABC transporter genes or had novel FKS mutations, respectively.

Epidemiology, practice patterns, and prognostic factors for candidemia; and characteristics of fourteen patients with breakthrough Candida bloodstream infections: a single tertiary hospital experience in Japan

Background

Candidemia is associated with high mortality, and its prognostic factors need to be examined in more detail in order to improve its management. A case of breakthrough (BT) candidemia is defined as the development of candidemia during antifungal therapy. The microbiological characteristics of and appropriate clinical practices for BT candidemia remain unclear.

Objectives

The primary objective of the present study was to identify the prognostic factors of candidemia, while the secondary objective was to elucidate the microbiological characteristics of patients with BT candidemia.

Materials and methods

A total of 121 patients diagnosed with candidemia between January 2007 and December 2016 were enrolled in this study. The primary outcome was the 30-day mortality rate.

Results

The overall incidence of candidemia was 0.056 cases/1000 inpatients. Among the 126 Candida isolated, C. albicans accounted for 36%, C. parapsilosis 26%, C. glabrata 12%, C. guilliermondii 14%, C. tropicalis 3%, C. pelliculos 1%, and other unidentifiable Candida species 8%. The 30-day mortality rate was 33%. In a multivariate Cox hazard analysis, C. albicans, the absence of antifungal therapy, age, lung disease, and mechanical ventilation were associated with a high mortality rate, whereas C. parapsilosis, the removal of a central venous catheter, and surgical wards were associated with a lower mortality rate. Fourteen patients had BT candidemia. A significant difference was observed in the proportion of C. guilliermondii and other Candida species exhibiting resistance to fluconazole and voriconazole, between patients with and without BT candidemia. Resistance to fluconazole was prominent in patients that developed candidemia with a history of azole antifungal agents.

Conclusion

The prompt initiation of antifungal therapy and removal of central venous catheter were essential for better outcomes. A class switch to other antifungal agents needs to be considered in empirical antifungal therapy for BT candidemia with a history of exposure to azole antifungal agents.

Echinocandins for management of invasive candidiasis in patients with liver disease and liver transplantation

Candida species remains one of the most important causes of opportunistic infections worldwide. Invasive candidiasis (IC) is associated with considerable morbidity and mortality in liver disease (LD) patients if not treated promptly. Echinocandins are often recommended as a first-line empirical treatment for managing IC and can especially play a critical role in managing IC in LD patients. However, advanced LD patients are often immunocompromised and critically ill. Hence altered pharmacokinetics, drug interactions as well as tolerance issues of antifungal treatments are a concern in these patients. This comprehensive review examines the epidemiology, risk factors and diagnosis of IC in patients with LD and evaluates differences between three available echinocandins for treating this group of patients.

Epidemiology and antifungal susceptibility of candidemia isolates of non-albicans Candida species from cancer patients

Candidemia is a growing concern worldwide, and its species distribution has shifted toward non-albicans Candida in recent decades, especially in patients with malignancy. This study aimed to update the epidemiology and antifungal susceptibility of non-albicans candidemia isolates from the cancer patients. Adult cancer patients with non-albicans candidemia were recruited, and clinical data were retrospectively collected from five medical centers in Taiwan from 1 July 2011 to 30 June 2014. In vitro susceptibility was determined by the broth dilution method using a Sensititre YeastOne system and interpreted according to the guidelines of the Clinical and Laboratory Standards Institute. A total of 346 episodes of non-albicans candidemia were identified in cancer patients. Candida tropicalis was the most common species (n=145, 41.9%) and had the highest resistance rate to fluconazole (n=17, 13.9%) among all the preserved isolates, including C. tropicalis, Candida glabrata and Candida parapsilosis. A higher Charlson comorbidity index, non-albicans candidemia due to C. tropicalis, neutropenia and septic shock were independent predictors of 28-day mortality. In conclusion, the species distribution and antifungal susceptibility of non-albicans candidemia isolates in our study differed from those in Western countries, providing useful information about local epidemiology for the selection of empirical antifungal agents for cancer patients.

Candidiasis and the impact of flow cytometry on antifungal drug discovery

INTRODUCTION

Invasive candidiasis continues to be associated with significant morbidity and mortality as well as substantial health care costs nationally and globally. One of the contributing factors is the development of resistance to antifungal agents that are already in clinical use. Moreover, there are known treatment limitations with all of the available antifungal agents. Since traditional techniques in novel drug discovery are time consuming, high-throughput screening using flow cytometry presents as a potential tool to identify new antifungal agents that would be useful in the management of these patients. Areas covered: In this review, the authors discuss the use of automated high-throughput screening assays based upon flow cytometry to identify potential antifungals from a library comprised of a large number of bioactive compounds. They also review studies that employed the use of this research methodology that has identified compounds with antifungal activity. Expert opinion: High-throughput screening using flow cytometry has substantially decreased the processing time necessary for screening thousands of compounds, and has helped enhance our understanding of fungal pathogenesis. Indeed, the authors see this technology as a powerful tool to help scientists identify new antifungal agents that can be added to the clinician's arsenal in their fight against invasive candidiasis.

Epidemiology and antifungal susceptibilities of yeast isolates causing invasive infections across urban Beijing, China

AIM

To investigate the species distribution and antifungal susceptibility profiles of yeast isolates causing invasive infections across Beijing.

MATERIALS & METHODS

A total of 1201 yeast isolates recovered from blood and other sterile body fluids were correctly identified by matrix-assisted laser desorption/ionization TOF MS supplemented by DNA sequencing. Antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute broth microdilution method.

RESULTS

Candida (95.5%) remained the most common yeast species isolated; Candida albicans (38.8%) and Candida parapsilosis (22.6%) were the leading species of candidemia. Azole resistances were mainly observed in Candida glabrata and Candida tropicalis isolates.

CONCLUSION

This study outlined the epidemiologic data of invasive yeast infections and highlighted the need for continuous monitoring of azole resistances among C. glabrata and C. tropicalis isolates in Beijing.

Strategies to Reduce Mortality in Adult and Neonatal Candidemia in Developing Countries

Candidemia, the commonest invasive fungal infection, is associated with high morbidity and mortality in developing countries, though the exact prevalence is not known due to lack of systematic epidemiological data from those countries. The limited studies report a very high incidence of candidemia and unique epidemiology with a different spectrum of Candida species. The recent global emergence of multi-drug resistant Candida auris is looming large as an important threat in hospitalized patients of developing countries. While managing candidemia cases in those countries several challenges are faced, which include poor infrastructure; compromised healthcare and infection control practices; misuse and overuse of antibiotics and steroids; lack of awareness in fungal infections; non-availability of advance diagnostic tests and antifungal drugs in many areas; poor compliance to antifungal therapy and stewardship program. Considering the above limitations, innovative strategies are required to reduce mortality due to candidemia in adults and neonates. In the present review, we have unraveled the challenges of candidemia faced by low resource countries and propose a ten part strategy to reduce mortality due candidemia.

Pharmacoeconomic analysis of antifungal therapy for primary treatment of invasive candidiasis caused by Candida albicans and non-albicans Candida species

BACKGROUND

Cost-effectiveness studies of echinocandins for the treatment of invasive candidiasis, including candidemia, are rare in Asia. No study has determined whether echinocandins are cost-effective for both Candida albicans and non-albicans Candida species. There have been no economic evaluations that compare non-echinocandins with the three available echinocandins. This study was aimed to assess the cost-effectiveness of individual echinocandins, namely caspofungin, micafungin, and anidulafungin, versus non-echinocandins for C. albicans and non-albicans Candida species, respectively.

METHODS

A decision tree model was constructed to assess the cost-effectiveness of echinocandins and non-echinocandins for invasive candidiasis. The probability of treatment success, mortality rate, and adverse drug events were extracted from published clinical trials. The cost variables (i.e., drug acquisition) were based on Taiwan's healthcare system from the perspective of a medical payer. One-way sensitivity analyses and probability sensitivity analyses were conducted.

RESULTS

For treating invasive candidiasis (all species), as compared to fluconazole, micafungin and caspofungin are dominated (less effective, more expensive), whereas anidulafungin is cost-effective (more effective, more expensive), costing US$3666.09 for each life-year gained, which was below the implicit threshold of the incremental cost-effectiveness ratio in Taiwan. For C. albicans, echinocandins are cost-saving as compared to non-echinocandins. For non-albicans Candida species, echinocandins are cost-effective as compared to non-echinocandins, costing US$652 for each life-year gained. The results were robust over a wide range of sensitivity analyses and were most sensitive to the clinical efficacy of antifungal treatment.

CONCLUSIONS

Echinocandins, especially anidulafungin, appear to be cost-effective for invasive candidiasis caused by C. albicans and non-albicans Candida species in Taiwan.

Revisiting Species Distribution and Antifungal Susceptibility of Candida Bloodstream Isolates from Latin American Medical Centers

The epidemiology of candidemia varies geographically, and there is still scarce data on the epidemiology of candidemia in Latin America (LA). After extensive revision of medical literature, we found reliable and robust information on the microbiological aspects of candidemia in patients from 11 out of 21 medical centers from LA countries and 1 out of 20 from Caribbean countries/territories. Based on 40 papers attending our search strategy, we noted that C. albicans remains the most common species causing candidemia in our region, followed by C. parapsilosis and C. tropicalis. In Argentina, Brazil, and Colombia, a trend towards an increase in frequency of C. glabrata candidemia was observed. Although resistance rates to fluconazole is under 3%, there was a slight increase in the resistance rates to C. albicans, C. parapsilosis and C. tropicalis isolates. Echinocandin resistance has been reported in a few surveys, but no single study confirmed the resistant phenotype reported by using molecular methods. We highlight the importance of conducting continuous surveillance studies to identify new trends in terms of species distribution of Candida and antifungal resistance related to episodes of candidemia in LA. This information is critical for helping clinicians to prevent and control Candida bloodstream infections in their medical centers.

A multi-centric Study of Candida bloodstream infection in Lima-Callao, Peru: Species distribution, antifungal resistance and clinical outcomes

Background

The incidence of candidemia is increasing in developing countries. Very little is known about the epidemiology of candidemia in Peru. The aim of this study is to describe the incidence, microbiology, clinical presentation and outcomes of Candida bloodstream infections in three Lima-Callao hospitals.

Methods

Candida spp. isolates were identified prospectively at participant hospitals between November 2013 and January 2015. Susceptibility testing for amphotericin B, fluconazole, posaconazole, voriconazole and anidulafungin was performed using broth microdilution method. Clinical information was obtained from medical records and evaluated.

Results

We collected information on 158 isolates and 157 patients. Median age of patients was 55.0 yrs., and 64.1% were males. Thirty-eight (24.2%) episodes of candidemia occurred in those <18 yrs. The frequency of non-Candida albicans was 72.1%. The most frequently recovered species were C. albicans (n = 44, 27.8%), C. parapsilosis (n = 40, 25.3%), C. tropicalis (n = 39, 24.7%) and C. glabrata (n = 15, 9.5%). Only four isolates were resistant to fluconazole, 86.7% (n = 137) were susceptible and 17 were susceptible-dose dependent. Decreased susceptibility to posaconazole was also observed in three isolates, and one to voriconazole. All isolates were susceptible to anidulafungin and amphotericin B. The most commonly associated co-morbid conditions were recent surgery (n = 61, 38.9%), mechanical ventilation (n = 60, 38.2%) and total parenteral nutrition (n = 57, 36.3%). The incidence of candidemia by center ranged between 1.01 and 2.63 cases per 1,000 admissions, with a global incidence of 2.04. Only 28.1% of cases received treatment within 72 hrs. of diagnosis. Overall, the 30-day survival was 60.4% (treated subjects, 67.4%; not-treated patients, 50.9%).

Conclusions

We found a very high proportion of non-albicans Candida species. Despite this, the decreased susceptibility/resistance to fluconazole was only 13.3% and not seen in the other antifungals. Overall, the incidence of candidemia mortality was high when compared to other international studies. It is possible, that the delay in initiating antifungal treatment contributed to the elevated mortality rate, in spite of low antifungal resistance.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Intra-abdominal Candida spp infection in acute abdomen in a quality assurance (QA)-certified academic setting

AIMS

To evaluate the contribution of light microscopy to detecting Candida spp infection in patients with complicated intra-abdominal infections (IAIs) admitted for acute abdomen to a quality assurance (QA)-certified surgical emergency ward.

METHODS

We conducted a retrospective study (2008-2012) of 809 abdominal intraoperative or biopsy tissue specimens obtained from patients admitted with acute abdomen and microbiological samples positive for Candida spp. Demographic data, mortality, comorbidities, specimen type, microscopy results, special histological staining performed, antimicrobial therapy were collected and analysed. Any comments at the multidisciplinary team meeting was recorded in minutes of and approved.

RESULTS

Sixty-six patients with complicated IAIs due to Candida spp were identified (39 male, 27 female, mean±SD age 75±20 years). Candida albicans was isolated in 35 cases and Candida non-albicans spp in 31 cases. Candida spp were isolated from blood in 50% of all selected microbiological specimens. Patients were stratified according to Candida spp (albicans vs non-albicans), underlying cancer disease and no previous antimicrobial administration, and a positive correlation with C. albicans isolation was found (p=0.009 and p=0.048, respectively). Out of 41 cases with microscopic evaluation, we identified yeast forms, pseudohyphae or both, indicative of Candida spp, in 23. Identification of Candida spp in histological specimens was higher in C. albicans cases than in C. non-albicans cases (73% vs 37.5%). Microscopy allowed prompt treatment of all patients.

CONCLUSIONS

Light microscopy still has great diagnostic significance, being a solid QA step. It provides rapid information and clues in patients who may harbour impaired defence mechanisms, concurrent chronic conditions and/or cancer.

Epidemiologic and microbiologic evaluation of nosocomial infections associated with Candida spp in children: A multicenter study from Istanbul, Turkey

BACKGROUND

The purpose of this study was to establish species distribution of Candida isolates from pediatric patients in Istanbul, Turkey, and to determine risk factors associated with nosocomial Candida infections.

METHODS

This study was conducted between June 2013 and June 2014 by participation of 7 medical centers in Istanbul. Candida spp strains isolated from the clinical specimens of pediatric patients were included. Clinical features were recorded on a standardized data collection sheet.

RESULTS

A total of 134 systemic Candida infections were identified in 134 patients. The patients were admitted in pediatric and neonatal intensive care units (41.8% and 9.7%, respectively) and in pediatric wards (48.5%). Candida albicans was the most prevalent species (47%), followed by Candida parapsilosis (13.4%), Candida tropicalis (8.2%), Candida glabrata (4.5%), Candida lusitaniae (3.7%), Candida kefyr (2.2%), Candida guilliermondii (1.5%), Candida dubliniensis (0.7%), and Candida krusei (0.7%). Types of Candida infections were candidemia (50.7%), urinary tract infection (33.6%), surgical site infection (4.5%), central nervous system infection (3.7%), catheter infection (3.7%), and intra-abdominal infection (3.7%). In multivariate analysis, younger age (1-24 months) and detection of non-albicans Candida spp was found to be risk factors associated with candidemia (P = 0.040; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.06-15.86; and P = 0.02; OR, 2.4; 95% CI, 1.10-5.53, respectively).

CONCLUSIONS

This study provides an update for the epidemiology of nosocomial Candida infections in Istanbul, which is important for the management of patients and implementation of appropriate infection control measures.

Antifungal susceptibility of Candida species isolated from patients with candidemia in southern Taiwan, 2007-2012: impact of new antifungal breakpoints

The Clinical and Laboratory Standard Institute (CLSI) revised the clinical breakpoints (CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C. albicans, C. tropicalis and C. parapsilosis to fluconazole, that of C. tropicalis and C. parapsilosis to voriconazole, that of C. tropicalis and Candida glabrata to anidulafungin and that of C. tropicalis, C. glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C. parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs.

Current trends in candidemia and species distribution among adults: Candida glabrata surpasses C. albicans in diabetic patients and abdominal sources

Candidemia rate and species distribution vary according to the type of patients, country of origin and antifungal prophylaxis use. To present current candidemia epidemiological trends. A retrospective examination of candidemia in adults (≥18 years-old) hospitalised from 2007 to 2015. Cases were identified through the microbiology laboratory. Candida species were distinguished based on colony morphology and VITEK-2 YBC cards, (bioMerieux, Durham, NC, USA). Patient characteristics, species distribution, source and outcome were assessed. We encountered 275 patients (294 episodes) with candidemia. The rate of candidemia dropped in 2010 (P = 0.003) without further decline. Nearly all cases (97.5%) were healthcare-associated. C. albicans (n = 118) and C. glabrata (n = 77) proportions varied without a discernable trend. C. glabrata was more common in diabetics [52.9% vs. 32.0% (non-diabetics); P = 0.004] and abdominal sources [53.3% vs. 35.5% (other sources); P = 0.03], especially gastric/duodenal foci [88.9% vs. 44.1% (other abdominal foci); P = 0.02]. All-cause 30-day mortality rate was 43.3% without changes over time or differences between C. albicans and C. glabrata. In conclusion, the candidemia rate remains stable after a decline in 2010. C. albicans remains the most common species but C. glabrata predominates in diabetics and abdominal sources. These findings suggest possible species-related differences in colonisation dynamics or pathogenicity.

Enterogenous infection of Candida albicans in immunocompromised rats under severe acute pancreatitis

BACKGROUND

Opportunistic infection of Candida albicans (C. albicans) has become a serious problem in immunocompromised patients. The study aimed to explore the mechanism of enterogenous infection of C. albicans in immunocompromised rats under severe acute pancreatitis (SAP).

METHODS

Sprague Dawley (SD) rats (n=100) were randomly assigned into 5 groups as the following: blank group, cyclophosphamide+ceftriaxone+SAP group, cyclophosphamide+ceftriaxone group, cyclophosphamide+SAP group, and cyclophosphamide group. The rats were sacrificed at 5 and 10 days, and their jejunum, colon, mesenteric lymph nodes, pancreas, intestinal content, and blood were quickly collected to detect C. albicans. A region of the 25S rRNA gene was chosen and amplified by polymerase chain reaction (PCR) to differentiate C. albicans genotypes. The amplified products were further sequenced and compared to judge their homology.

RESULTS

Compared with the Cyclophosphamide group, the combination of immunosuppressants and broad-spectrum antibiotics significantly increased the colonization of C. albicans in intestine in 5 and 10 days. Pure SAP stress did not increase the opportunistic infection of C. albicans. The PCR products of C. albicans isolates all belonged to the genotype A family, and sequence alignment showed that the amplified fragments were homologous.

CONCLUSION

The damage of immune system and broad-spectrum antimicrobial agents are important risk factors for opportunistic fungal infection. Intestinal tract is an important source for genotype-A C. albicans to translocate and invade into bloodstream.

Antifungal activity and mode of action of thymol and its synergism with nystatin against Candida species involved with infections in the oral cavity: an in vitro study

BACKGROUND

Limitations of antifungal agents used in the treatment of oral candidiasis, as the development of resistant strains, are known by the scientific community. In this context, the aim of this study was to evaluate the antifungal activity of thymol against Candida albicans, Candida tropicalis and Candida krusei strains and to determine its mode of action and synergistic effect when combined with the synthetic antifungal nystatin.

METHODS

The minimum inhibitory concentration (MIC) was determined using a microdilution technique, and the minimum fungicidal concentration (MFC) was determined via subculture sowing. The mode of action of thymol was established by verifying fungal growth in the presence of sorbitol or ergosterol. The fractional inhibitory concentration index (FIC) was determined using the checkerboard method.

RESULTS

Thymol presented an antifungal effect, with MICs of 39 μg/mL for C. albicans and C. krusei and 78 μg/mL for C. tropicalis. The results of the antifungal test remained unchanged in the presence of sorbitol; however, the MIC value of thymol against C. albicans increased eight times (from 39.0 to 312.5 μg/mL) in presence of exogenous ergosterol. The combination of thymol and nystatin reduced the MIC values of both products by 87.4%, generating an FIC index of 0.25.

CONCLUSIONS

Thymol was found to have a fungicidal effect on Candida species and a synergistic effect when combined with nystatin.

Candida species epidemiology 2000-2013: a laboratory-based report

OBJECTIVE

To describe a prospective laboratory-based surveillance of Candida species that were collected from different anatomical sites of patients admitted to the University of Malaya Medical Centre, Malaysia, from the year 2000 to 2013.

METHODS

Conventional (culture, microscopic examination and carbohydrate assimilation test) and molecular (PCR amplification and DNA sequencing) techniques were used to identify Candida species.

RESULTS

A total of 16 Candida species isolated from 34 392 clinical samples were from the oral cavity (oral swabs and throat swabs), blood, respiratory tract (sputum, tracheal secretions, nasopharyngeal aspirates, bronchoalveolar lavage), high vaginal swab, pus and urine. C. albicans (66.70%, 22 941/34 392), C. glabrata (11.71%, 4029/34 392), C. parapsilopsis (10.74%, 3692/34 392), C. tropicalis (9.19%, 3162/34 392) and C. krusei (1.15%, 396/34 392) were the five predominant Candida species. C. albicans was the predominant species isolated from the oral cavity, respiratory tract and high vaginal swab; while the Candida species isolated from blood, urine and pus were predominant non-albicans Candida. Uncommon Candida species, such as C. lusitaniae, C. haemulonii, C. humicola, Pichia ohmeri and C. ciferrii, were also isolated in this study.

CONCLUSION

Our study expands the current knowledge of the epidemiology of non-invasive and invasive candidiasis in Malaysia. The variability of the Candida species distribution from different anatomical sites highlights the significance of local epidemiology in disease management and selection of antifungal agents.

Host response to Candida albicans bloodstream infection and sepsis

Candida albicans is a major cause of bloodstream infection which may present as sepsis and septic shock - major causes of morbidity and mortality world-wide. After invasion of the pathogen, innate mechanisms govern the early response. Here, we outline the models used to study these mechanisms and summarize our current understanding of innate immune responses during Candida bloodstream infection. This includes protective immunity as well as harmful responses resulting in Candida induced sepsis. Neutrophilic granulocytes are considered principal effector cells conferring protection and recognize C. albicans mainly via complement receptor 3. They possess a range of effector mechanisms, contributing to elimination of the pathogen. Neutrophil activation is closely linked to complement and modulated by activated mononuclear cells. A thorough understanding of these mechanisms will help in creating an individualized approach to patients suffering from systemic candidiasis and aid in optimizing clinical management.

Clinical and microbiological investigation of fungemia from four hospitals in China

In this study, fungemia cases from four tertiary hospitals located in Shanghai and Anhui province in China from March 2012 to December 2013 were enrolled to investigate clinical features, species distribution, antifungal susceptibility and strain relatedness. During the study period, 137 non-duplicate cases and their corresponding isolates were collected. Six different genera of fungi were identified, of which Candida spp. were the most common (126/137, 91.97 %), with C. albicans predominating (48/137, 35.03 %). The non-Candida fungi rate reached 8.03 % (11/137), and Pichia spp. was the most common (5/137, 3.65 %). Compared with C. albicans, non-C. albicans fungi-associated fungemia was more likely in younger (p = 0.004) and male patients (χ (2) = 6.2618, p = 0.0123) and patients from ICUs (χ (2) = 6.3783, p = 0.0116). Overall, the susceptible/WT rates of common Candida spp. to fluconazole, itraconazole, voriconazole, flucytosine, amphotericin B and caspofungin were 74.63, 92.31, 93.16, 96.58, 100 and 95.69 %, respectively. C. tropicalis and C. guilliermondii had a low susceptibility to fluconazole: 79.95 and 77.78 %, respectively. No isolates were resistant/WT to caspofungin, but C. parapsilosis and C. guilliermondii had high MIC90 values; 1 and 2 mg/L, respectively. In terms of genotyping, MLST was taken for C. glabrata and C. tropicalis, while microsatellite marker analysis was used for C. albicans and C. parapsilosis. C. glabrata was predominantly clone ST7, accounting for 75 %, while the other isolates showed genetic diversity. Considering the increased proportion of non-C. albicans fungi and the presence of endemic clones of C. glabrata, it is essential to undertake additional surveillance of fungemia.